High-Temperature Drying of Thick Concrete Slabs

The foremost requirement for deep polymer impregnation of thick concrete slabs is thorough drying to remove all evaporable water from the pore system in concrete. To facilitate rapid repair of bridge decks with polymer impregnation, it is desirable to dry the concrete from the surface with surface temperatures not exceedings 700-800°F (370-420°C). A time-temperature-moisture loss study is presented on six 24x24x6-in.(610x610x150-mm) concrete slabs, a 72x72x8-in.(1800x1800x200-mm) slab and a small section of 7-1/2-in. (190-mm) bridge deck. The specimens were dried from one surface using an automated propane gas fired torch assembly. The feasibility of high-temperature drying of concrete without cracking problems is demonstrated and a criterion for safe and rapid drying to the depth of 4-6-in.(100-150-mm) in the field is developed.